The present invention relates to a torsion damping device for an automobile clutch friction disc, comprising two coaxial parts adapted to move angularly relative to one another through a limited displacement against the action of first resilient means, one of said parts comprising a web and a hub which are coaxial and are movable angularly relative to one another against the action of second resilient means within a sector of angular displacement defined by complementary toothings of the web and hub, the toothings having circumferential play therebetween.
A torsion damping device of this kind makes it possible to achieve regulated transmission between one of the parts, which is associated with an input shaft, and the other part, which is associated with an output shaft, in order to prevent the generation of vibrations, particularly acoustic vibrations, along the entire kinematic chain in which the torsion damping device is inserted.
This is the purpose of the resilient means which oppose an angular displacement between the two parts of the torsion damping device.
With regard to the second resilient means, which oppose the angular displacement between the web and the hub, their purpose is to prevent the production of various noises, for example gearbox noise, which is also called "neutral" noise, when the torque transmitted is zero or low.
Torsion damping devices of this kind, which comprise first resilient means and second resilient means, are generally satisfactory under various operating conditions. However, it has been found that when the torque is reversed in the course of operation the complementary toothings of the web and hub, which toothings have circumferential play therebetween, are liable to clash noisily.
It is an object of the present invention to provide a torsion damping device for an automobile clutch friction disc of the type indicated above, in which this disadvantage is minimized or eliminated and in which the circumferential striking action of the toothings of the web and hub against one another is softened, without impairing its effectiveness.